Trees can grow for hundreds of years yet, a tree surgeon armed with a chainsaw can bring them down in minutes with thanks to the invention of the chainsaw. It seems criminal to fell such a fantastic specimen, but tree felling is often very necessary.
When trees die, they die from the inside outwards and can become dangerous. Oftentimes, trees will fall and block roads or train tracks and will need chopping and clearing quickly.
After a natural disaster or a tree emergency, a chainsaw can be a welcome sound. Chainsaws are not all about destruction, they are a useful tool for the management of woodland.
As well as for tree felling, they are used for tree pruning, tree reduction, tree shaping and tree pollarding. In order to maintain woodland and its habitats, tree thinning, and clearing is necessary. But what is a chainsaw exactly and how does one work? Let’s have a closer look.
The Invention of the Chainsaw: What Is A Chainsaw?
There are clues in its name of course – a chainsaw has two main parts: a chain and a saw blade. The sawblade is built into the chain, which is located along a metal guide bar.
A chainsaw usually has a petrol engine, but you can get electric chainsaws that are powered by mains electricity or battery packs.
The chain itself is not dissimilar to the chain you will find on your bicycle. It runs around gear wheels (sprockets) and has around 30 ‘teeth’ that are made from a really hard steel alloy.
The Invention of the Chainsaw: How Does the Chainsaw Work?
Traditional chainsaws will use a two-stroke petrol engine with a 30cm3 to 120cm3 cylinder volume.
When the engine is running, a piston will move in and out of the cylinder. This pushes a rod that then turns the crankshaft. The crankshaft is responsible for turning the gears. The gears are connected to a sprocket and so the chain will spin around.
The Invention of the Chainsaw: Who Invented the Chainsaw?
Samuel J. Bens from San Francisco sought a patent for his “endless chainsaw” in July 1903. This was granted around 18 months later in January 1905.
The patent application included drawings of his sawing machine as it sliced a tree trunk. This patent, however, didn’t specify how the chainsaw would be powered. In 1921, Bens filed a patent for a chainsaw that was portable.
The Chainsaw Was Invented for Childbirth…
Though we’ve just read about Samuel J. Bens and his U.S. chainsaw patents. There is another chainsaw invention that pre-dates his creations.
The original chainsaw was invented to assist mothers during childbirth. Yes, you read that correctly! The procedure was called a symphysiotomy and was a way of assisting a woman to give birth quickly.
Back in the 18th century, childbirth was a very risky and dangerous time for women. People weren’t generally as healthy as they are today and if complications arose during labour, they often had dire consequences.
Nowadays, caesarean sections are commonplace procedures for women who have difficulties birthing naturally but back then these were risky since they carried a risk of infection and anaesthesia was a few years away.
Symphysiotomies were popularized from 1597 and were the most common way of getting a baby out of the womb as quickly as possible. You don’t hear of this procedure these days because it’s been denounced. After all, it involves cutting the mother’s pelvis in half.
James Jeffray and John Aitken, two doctors from Scotland, discovered that performing a symphysiotomy with a single blade was very time-consuming, not very accurate and excruciating. Thus, they created a chainsaw-like device that would be more precise and quicker.
The first prototype had a long chain with teeth that were serrated. This had a handle on each end and resembled a wire saw. The doctors would wrap the chain around the pelvic bone and alternate pulling the handles.
Bernhard Heine refined this saw and developed the osteotome. This was powered with a hand crank. The chain was wrapped around a blade that rotated.
With the popularization of anaesthesia, this osteotome became widely used, even in other operations and dissections.
Recovering from a sawn pelvis obviously took a long time and so, as hospital hygiene rose and general anaesthesia developed, doctors began favouring the caesarean section.
It is said that Samuel J. Bens got his ideas from the osteotome, but thankfully chainsaws have stopped being used on people!
What Can A Chainsaw Be Used For?
Chainsaws are not just used for tree felling. They’re used for tree pruning, tree crown lifting, tree shaping and lots of other tree maintenance techniques including stump grinding.
Trees aside, there are other uses for chainsaws. You can get specialist chainsaws that are used to cut concrete. Artists also have been known to use chainsaws to do ice sculptures, for example.
Chainsaws: Advantages and Disadvantages
As with many tools used for tree maintenance, chainsaws have advantages and disadvantages.
The biggest advantage of chainsaw use is speed. You can drastically reduce your sawing time by using a chainsaw over a hand saw.
A chainsaw can be up to ten times quicker. Not only that, but the effort involved is minimal in comparison. You expend a lot less energy felling a tree with a chainsaw than with a handsaw.
There are two main disadvantages to using a chainsaw and these are maintenance and safety.
Chainsaws are dangerous. Even when used by a strong adult that has been fully trained in chainsaw use, they are still inherently dangerous.
The biggest safety risk occurs because of ‘kickback’. Kickback happens when the chainsaw chain catches and gets stuck, but the engine keeps the saw turning. This means that the whole chainsaw will fly upwards towards your head, which can obviously cause serious or fatal injuries.
If you want to know more about the science behind kickbacks, it’s all due to Newton’s 3rd law of motion. In order to protect yourself in some way, you can get chainsaw helmets that have visors.
In terms of other safety equipment, you can get chainsaw clothing, which is made from nylon or other synthetic materials that will snag on the teeth of the chainsaw and stop it from turning. Even with all the safety gear, you still need to bear in mind that you are using something that is lethal.
The second big disadvantage of a chainsaw is how much maintenance you must carry out. Obviously, a handsaw needs very little, if any, maintenance. Any sawdust produced simply falls.
When you’re using a chainsaw, however, the sawdust gets into the mechanisms. This causes problems because it mixes with the lubricating oil. The result is a gungy substance that needs regularly removal.
Most chainsaw manuals will have a maintenance guide that tells you what to do weekly, monthly or yearly. So, although you will save time during the act of chopping wood, you will lose some time carrying out necessary chainsaw maintenance.